Currently, manufacturing of a substrate must be completed through a number of processes which are carried out at different places. Accordingly, during the manufacturing process, a substrate transferring system must be used to transfer the substrate between different processes.
Referring to FIG. 1, there is shown a top view of a conventional substrate transferring system. The conventional substrate transferring system comprises a first substrate processing stage 40 and a second substrate processing stage 41, a substrate transferring stage 42, a substrate traversing stage 43, a substrate outlet stage 44 and a vacuum adsorption device 45. The substrate transferring stage 42 comprises a first roller-type transferring mechanism 421, the substrate traversing stage 43 comprises a second roller-type transferring mechanism 431 and a track 432, and the substrate outlet stage 44 comprises a third roller-type transferring mechanism 441.
Referring to FIG. 2 through FIG. 6, the conventional substrate transferring system operates as follow.
Firstly, as shown in FIG. 2, a first substrate 4001 and a second substrate 4002 are prepared by the first substrate processing stage 40 and the second substrate processing stage 41 respectively, and the first substrate 4001 is adsorbed by the vacuum adsorption device 45.
As shown in FIG. 3, the first substrate 4001 is transferred by the vacuum adsorption device 45 from the first substrate processing stage 40 to the substrate transferring stage 42.
As shown in FIG. 4, the substrate traversing stage 43 moves along the track 432 to a position aligned with the substrate transferring stage 42 to receive the first substrate 4001 transferred from the first roller-type transferring mechanism 421 of the substrate transferring stage 42; meanwhile, a third substrate 4003 is loaded onto the first substrate processing stage 40.
As shown in FIG. 5, after receiving the substrate 4001, the substrate traversing stage 43 moves towards the substrate outlet stage 44 along the track 432; meanwhile, the second substrate 4002 is adsorbed by the vacuum adsorption device 45 from the second substrate processing stage 41 onto the substrate transferring stage 42.
As shown in FIG. 6, the substrate traversing stage 43 moves to the substrate outlet stage 44 along the track 432, and transfers the first substrate 4001 to the substrate outlet stage 44 by means of the second roller-type transferring mechanism 431; meanwhile, a fourth substrate 4004 is loaded onto the second substrate processing stage 41.
However, the conventional substrate transferring system described above has the following drawbacks:
(1) the substrate traversing stage 43 is only able to receive one substrate at a time, and the substrate is transferred by a means of roller-type mechanism, so the transferring speed is relatively low and is only about 350 mm/s; and
(2) the substrate traversing stage 43 is only able to transfer one substrate at a time. As shown in FIG. 6, when the first substrate 4001 is being transferred to the substrate outlet stage 44, the second substrate 4002 to be transferred next to the substrate traversing stage 43 is already waiting at the substrate transferring stage 42. However, the substrate traversing stage 43 will not return back until the substrate 4001 is transferred to the substrate outlet stage 44; moreover, only when the substrate traversing stage 43 returns back to the position aligned with the substrate transferring stage 42 as shown in FIG. 1, can the substrate transferring stage 42 transfer the next substrate 4002 to the substrate traversing stage 42 for transferring of the next substrate 4002.
Referring to FIG. 7, there is shown a schematic view of the tact time of the conventional substrate transferring system. Taking a 32-inch substrate as an example, the bottleneck of the conventional substrate transferring system exists in the substrate traversing stage 43: the tact time thereof is 17 seconds, which makes it impossible to transfer the substrate rapidly. Accordingly, the conventional substrate transferring system suffers from a low transferring speed, and this may lead to jamming of the substrates, decrease in throughput of the whole production line and degradation in the production efficiency.
In view of this, an urgent need exists in the art to provide a substrate transferring system and a substrate transferring method that can increase the substrate transferring speed and shorten the substrate transferring period.